The present invention relates to a trocar sleeve, as well as further to the associated trocar.
A trocar is an instrument, with whose help one creates an access to a body cavity in particular the abdominal cavity, with minimal evasive surgery. A trocar sleeve which is inserted together with the trocar and which holds open the later access into the body cavity, belongs to the trocar. The trocar together with the trocar sleeve is introduced, for example, through the abdominal wall, whereupon the trocar is pulled out and the introduction of instruments such as optical tools, gripper tools, cutter tools or other tools may be effected via the remaining trocar sleeve.
In order to fasten the trocar sleeve, for example, in the abdominal wall, it is counted as belonging to the state of the art to provide this with a suitable thread, for example, with a spiral arranged in a helical manner, at the distal end. Such trocar sleeves are known from U.S. Patent Application Publication No. 2008/0255519 A1 (Picksun). In Picksun, a trocar sleeve is particularly described by way of FIGS. 24 and 25, whose distal end section on the outer side is provided with a spiral and which at the proximal side, merges into region widened in a funnel-like manner. The trocar sleeve is to be reliably fastened in the wall of the body cavity, e.g., the abdominal wall, amid the compression of this, by way of the thread. The instruments thereby are to be introduced through the comparatively narrow cylindrical inner cross section, and a guide in the distal end section is provided there for a laparoscope or endoscope optics, but this guide however additionally limits the remaining cross section and thus additionally makes the introduction of further instruments more difficult. The trocar sleeve of Picksun is also not suitable for receiving a trocar.
A trocar sleeve in the form of a conical insert is known from German Publication No. 10 2005 026 467 A1 (Cuschieri), and comprises a spiral on the outer periphery and a guide for an instrument on the inner side. Since the guide is arranged parallel to the conical wall, the instrument may only be introduced and held, in this direction. Although the circular free space formed at the distal end, for the passage into the body cavity, is largely free of the guide due to the oblique leading, however the arrangement parallel to the wall necessitates an oblique guiding of the instrument, by which means the access is practically likewise narrowed. The conical outer side with the spiral arranged thereon furthermore does not provide for a sufficient grip, since a compression of the abdominal wall with this arrangement may not be effected and thus a more secure grip is not guaranteed.